A person wears a hearing aid to improve his/her impaired hearing. Acoustic signals from the environment are received through an input aperture in the hearing-aid case into the hearing aid proper, wherein the signals are processed according to the said impairment. The processed signal is then fed through a so-called acoustic duct and through an output aperture into the inner ear. Such hearing aids, when used daily, will soil and the soiling will partly affect the acoustic behavior of the elements of acoustic-wave carriers. As a result of the change in the acoustic behavior, the actual function of the hearing aid can be implemented only in a restricted way.
Accordingly, proposals have been advanced to fit the acoustic input and output apertures with a protective element to prevent soiling penetration. Reference is made in this regard to the European patent document 0,847,227 A. When the protective elements are soiled to some extent, they must be replaced by new ones to restore the hearing-aid function to its optimal condition.
However, as regards the known hearing aids, exchanging the protective elements is fairly laborious and complex. Frequently, substantial hearing-aid parts, such as a full horn, must be replaced because the lids are bonded to this horn.
Therefore, there exists a need in the art for a hearing aid that has simple and reliably replaceable protective elements.
The present invention is directed toward a hearing aid that allows simple and reliable exchange of protective elements.
The present invention offers several advantages. The horn is rotatably supported inside the hearing-aid case. The lid is freed, by rotating the horn from a hearing-aid operational position into a hearing-aid servicing position. The lid, which covers and forms an acoustic input aperture, can be exchanged in a simple and rapid manner. Advantageously, the lid is in the shape of a wedge, partly interrupted by a guide slot, and preferably is made of an open-pore material.